Backup Compass and Depth Gauges

[Dives4Fun]

I am planning on solo diving after I get sidemount training. I am using a Perdix AI for my primary computer but my other computer is a hose integrated computer or a hose integrated analog pressure/depth gauge so wont be suitable with the sidemount rig.

To start I am only going to do open water solo diving and ideally would have another Perdix as backup to keep the tables the same but the reality is I dont have that kind of money. I am going to stick within no-decompression recreation limits and diving will be in lakes.

Since I am going to go AI and I have SPG's on the regulators I will have gas pressure redundancy. What I dont have is a depth gauge and compass backup. I was thinking of getting a "puck" version of each of these and then making some kind of holder for them to keep them together.

My other thought is I may not even need a compass - the lakes I am talking about are not huge open bodies of water. Any thoughts on this setup?

 

[JohnN]

I am planning on solo diving after I get sidemount training. I am using a Perdix AI for my primary computer but my other computer is a hose integrated computer or a hose integrated analog pressure/depth gauge so wont be suitable with the sidemount rig.

To start I am only going to do open water solo diving and ideally would have another Perdix as backup to keep the tables the same but the reality is I dont have that kind of money. I am going to stick within no-decompression recreation limits and diving will be in lakes.

Since I am going to go AI and I have SPG's on the regulators I will have gas pressure redundancy. What I dont have is a depth gauge and compass backup. I was thinking of getting a "puck" version of each of these and then making some kind of holder for them to keep them together.

My other thought is I may not even need a compass - the lakes I am talking about are not huge open bodies of water. Any thoughts on this setup?

I think you need to decide what (potential) problems you're trying to solve.

I carry a backup computer because all of my diving requires a substantial drive or flight (minimum 5-6 hour drive round trip), so missing a second dive would be a huge bummer. My computers are from the same mfg, but I don't consider that necessary. If the distance to dive is not an issue for you, thumb the dive and ascend. If it is, pick up an inexpensive backup (for example there is a new Suunto Vyper being offered on the board for $150), it may be more conservative than your Perdix, but do you really care, since it is there just in case your primary gives up?

If you dive sites that require a compass for navigation (it doesn't sound like it), a good analog compass is always prudent. But you need to examine the downside. If it just means a longer surface swim, it may not be worth it.

 

[Akimbo]

I think you need to decide what (potential) problems you're trying to solve.

Exactly. One option is to just go shallow and finish the dive if the computer dies -- not always possible on boat dives.

 

[aquacat8]

If you’re not using your old analog pressure/depth gauge you could always pop the depth gauge out of the console and put it in a bungee mount and stick it anywhere convenient

 

[Rred]

My first thought is would you need a redundant depth gauge? Since you have an integrated system, if it fails you would probably bail and end the dive then and there, no? In which case you only need to know your ascent rate (back to bubblewatching) which a simple depth gauge won't help with anyway. And a safety stop of 10-15' doesn't really need a gauge.

Which leaves the compass. Unless you've got big lakes and like to dive at night in the fog...wouldn't prominent landmarks on the surface be enough? Or are you sightseeing, navigating on the bottom? A small inexpensive compass, worn on a watchband or other "toy" ball compass is surprisingly robust and if you're not staying on the bottom doing SAR patterns...for $2-10 certainly is a functioning backup to tell you North versus South.

 

[Dives4Fun]

Ok, thanks all.

I was overthinking this whole thing and I certainly dont need a compass - the lake is small and surfacing will show you exactly where you are. I was thinking a backup depth gauge for the safety stop but that could easily be done with an smb and line with a 15' or 20' knot.

 

[mdax]

I always wear a compass, don't have backup pressure gauge and go with perdix + uwatec for depth and time redundancy.

 

[northernone]

Here's another collection of ideas for consideration:

99 cents buys a liquid filled compass online, it tucks away until needed, no clutter, no entanglement risk. Not unless it's necessary, leave the spare behind. How often does a compass fail, and what consequence would that result in?

If you're in an open lake, no reason you can't sidemount your tanks and keep your consoles attached, loop the hose under an elastic tank band (slice of inner tube).

A matter of perspective for my recreational diving. If my timing device fails, I'm ending my dive and surfacing. No need for a redundant timer, my dive is ended. I'll do a safety (optional) stop song and call it a day, I don't need a second dive immediately. I carry redundant dive computers depth/time devices when I have necessary multiple dives or deco obligations where careful timing is needed.

 

[Doc Harry]

I can't imagine going down without some way to navigate, especially in low viz.

I've had a compass fail when I needed one, and thankfully I had a backup compass.

 

[АлександрД]

add small pocket to your equipment and put there four things:

how to made - is here

and Minimum Deco Table DIR-diver.com - Using the min deco table